First commit

go.mod

@@ -0,0 +1,9 @@
+module git.bit5.ru/backend/trc
+
+go 1.13
+
+require (
+	git.bit5.ru/backend/colog v1.0.0
+	git.bit5.ru/backend/errors v1.0.0
+	github.com/google/uuid v1.3.0
+)

go.sum

@@ -0,0 +1,2 @@
+github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
+github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=

trc.go

@@ -0,0 +1,42 @@
+package trc
+
+import (
+	"fmt"
+	"net/http"
+
+	"git.bit5.ru/backend/colog"
+	"git.bit5.ru/backend/errors"
+	"github.com/google/uuid"
+)
+
+type TraceId string
+
+func NewTraceId() TraceId {
+	return TraceId(uuid.New().String())
+}
+
+type SpanId string
+
+func NewSpanId() SpanId {
+	return SpanId(uuid.New().String())
+}
+
+//-----------------------------------------------------------------------------
+
+const TraceIdHeaderName = "trace-id"
+
+func RequestTraceId(req *http.Request) (TraceId, error) {
+	traceIdStr := req.Header.Get(TraceIdHeaderName)
+	if len(traceIdStr) == 0 {
+		return "", errors.New("Trace id must be specified.")
+	}
+
+	return TraceId(traceIdStr), nil
+}
+
+//-----------------------------------------------------------------------------
+
+func NewTraceLogger(logger *colog.CoLog, traceId TraceId) *colog.CoLog {
+	prefix := fmt.Sprintf("[trace_id:%s]", traceId)
+	return logger.Clone().AddPrefix(prefix)
+}

trc_test.go

@@ -0,0 +1,15 @@
+package trc_test
+
+import (
+	"testing"
+
+	"git.bit5.ru/backend/trc"
+)
+
+func TestNewTraceId(t *testing.T) {
+	traceId := trc.NewTraceId()
+
+	if len(traceId) == 0 {
+		t.Error("Empty traceId.")
+	}
+}